Building New Email List for New Partner Site
I am about to launch a new, partner website in a much broader sector in the construction industry. Email marketing works on our current site so I was considering an investment in several large email lists for each of the categories on the new site.
I've read that opt-in is the most effective method, which we currently use, but we've also hired help to expand our email list with our current site in the past. This has worked, but I wanted to look for any feedback before doing so on the new site.
Have these heavy-traffic sites developed their massive email lists with 100% opt-in? I find that hard to believe.
Thanks to anyone who can offer input.